What is the Wrinkle Shield™ feature and how do I use it?

The WRINKLE SHIELD™ feature provides 90 minutes of heat-free, periodic tumbling at the end of a drying cycle to help prevent wrinkles from forming when you cannot remove clothes immediately. You can turn the WRINKLE SHIELD™ knob to on or off at any time before the cycle has ended. On some models, the feature automatically provides 40 minutes of heat-free tumbling.